Filter element



June 10, 1952 1 V, BAUER ETAL 2,599,604

` FILTER ELEMENT Filed July 13, 1949 3 Sheets-Sheet l June 10, 1952 J. v. BAUER HAL FILTER ELEMENT 5 Sheets-Sheet 2 Filed July 1 3, 1949 lala/z Vga-fuer and fg//JL 24H95 June 10, 1952 J, v,l BAUER TAL 2,599,604

FILTER ELEMENT Filed July 13. 1949 5 Sheets-Sheet .'5

Patented June 10, 1952 FILTER ELEMENT Jordan V. Bauer, Elmwood Park, and Russell H. Curtis, St. Charles, Ill.

Application `July 13, 1949, Serial No. 104,472 6 Claims. (Cl. ZIO- 169) This invention relates to a new and improved type of filter for the removal of solid particles from fluids and to the construction thereof. The invention more particularly relates to a new and improved type of oil filter for use in internal combustion engines.

One of the objects of the present invention is to provide a filter element which is compact in size and shape and which will have unusually high flow properties and long filtration life.

Another object is to provide a filter element which will have an unusually large filtering surface area.

Another object is to provide a filter which is constructed of readily available materials and which is low inrcost and simple to manufacture.

A further object of the invention is to provide a filtering medium which will beresistant to the action of hot oil and contaminating substances normally present therein.

A still further object is to provide a filtering medium which will provide a large surface area, but which will also be rigid enough to withstand considerable fluid pressures Without distortion.

Another object of the invention is to provide a compact filter element by employing corrugated paper in a unique construction.

These and other objects of the invention will become more apparent upon consideration of the following description land the drawings in which:

Fig. 1 illustrates a strip of corrugated single faced paper as employed in the practice of the invention;

Fig. 2 represents one of the methods by which the corrugated paper may be constructed 'into a lter element;

Fig. 3 illustrates another embodiment of the invention by which the corrugated paper is processed into a filter element;

Fig. 4 shows still another embodiment wherein the ends of alternate corrugations are sealed with a cement or adhesive;

Fig. 5 is a view, partly in section, showing the finished filter element of the invention;

Fig. 6 is a top plan view of the illter element of Fig. 5;

Fig. '7 is a side view of an automotive oil filter showing in partial section the completed filter element of Fig. 5 enclosed therein; and

Fig. 8 is a top plan view of thel automotive filter of Fig. 7.

According to the present invention, a filter for the removal of solid particles from fluids is pre-` pared by inserting a fllter element having novel and unusual characteristics into a casing through which the fluid to beiiltered is circulated. The filter element contains a filtering medium which is characterized by a large surface area, structural strength to resist fluid pressures, long life and good flow properties. This novel filtering medium comprises a strip of a single faced corrugated paper in which alternate corrugations are sealed at opposite ends of the corrugations.

To form the filter element, one end of the single faced corrugated strip is bonded to a core and then convolute wound around the core to form a cylindrical unit with the flutes of the corrugations running parallel to the axis of the core. As the corrugated strip is wound (or prior to the winding) the open ends of the confined flutes are sealed shut along one edge of the strip. During the winding operation the alternate open flutes of the corrugated paper strip likewise become confined. The open ends of these alternate flutes are sealed shut along the opposite edge of the strip. After the unit has been wound,`

the free end of the strip is bonded to the body of the unit with a piece of gummed tape or other adhesive means so as to prevent unwinding. `The result is a cylindrical filter unit wherein any fluid passing into the non-sealed flute openings at one end must pass through the paper walls of the corrugations and emit from the openings formed by the alternate non-sealed flutes atthe opposite end. In this manner an unusually large area of filtration surface is made available, and the ratio of this area to the outside dimensions o'f the unit is large.

Single faced corrugated paper is a well known `productwhich is manufactured in large quantities and is used for the most part as a protective packing or wrapping material. High speed manufacture consists of corrugating one web of 9, paper by means of heated fluted rolls, applying an adhesive to the tips of the corrugations and then bringing the corrugated web into contact with a flat web of paper and forming a bond between the two sheets. The resultant single faced corrugated paper comprises a corrugated sheet `bonded at the tips of the corrugations to a flat sheet of paper.

With reference to the drawings, Fig. l illustrates a strip of corrugated single faced paper `prepared according to a method which will be describedin greater detail hereinafter. The strip of corrugated paper l is composed of a flat paper web 2, and a corrugated paper web 3 suitably attached at the valleys of the corrugations to the flat web 2,` thereby forming a series of flutes 4.

The corrugations 3 have been flattened along one edge 5 and the flutes 4 have been closed along the edge 5 by sewing the upper web 3 to the lower web 2. This method represents a simple means of closing one end of the utes in the preparation of the corrugated paper for use as a filtering medium.

In Fig. 2 a strip of corrugated paper sewed at one edge as in. Fig. 1 is further constructed into a lter elementiaccordineito thepracticefofthisz.

invention: In Fig. 2 the paper strip', having-af sealed end sewed edge 1 is convolute wound around a cylindrical core 8 n the preparation of a cylindrical lter element. The utts;v 8 having been sealed at the edge 1, it is now desited to seal the alternate flutes leinorder-thatthe passage ofY liquid between flutesv carrbeaocomplished only by passing throughga'elayerof paper. by the application of a self-hardening semi-fluid cement Il which is applied as illustrated by an extruding nozzle |2411. Ai.. siifcientv amountof; cement l applied alone the: edge-z of; the..Vv paper stripssp.:that alternateflutest terminating f ati this; edge will besealed when the: 13a-DeiA isY woundv about the `cylindrical core.:

tpreferred;v method of: manufacture ofl the presentiilter elementis illustrated n'xEg. 3;.- Asi showntherein,-. a; cylindricaly core ItV is mounted upon iarotatingmandrel I4 and; is.; adaptedtoA be rotatedthereby;l Thecorrugatedstripl is at.` taclred:` tdthe core.; t3 by meansu oiapaperA leader strip |15.whicheis.;passedgaboutfthexcorc 1,3... A'.

strip `of corrugated paper; isemployed ,suchas the one edge of the,

one: shown-miie.; lain whY stripg-issewed at4 Sftozgthereby fecal alternate flutes:

offtlie. corrugated; paper:4A Blotationlo;theqcorel bri-means; or' the=..mandre1;. IA causes.-V theA corniu getedpaper: tobe-corrvoli-itewoundY about the-core.

wound. a.. self the.; corrugat fl is extrudedfrom tlieinozzle. t8 a the; upwardly facing: -iiutesxand ,1 operatesf to seal,

thef iiutes.- durinsff the.. winding: operation.- The;

ilpteszzsealedtbyf the :Cement re; alternate utes fronrgthosegwhichf,aresealed thegsewingoperatieni: Thetsprineloaded;pressuremellzn assists-` ven wind; or; the.;corrugated`V ormine V'tight e thefcementd base;I I nemberY 2/3- and..- the;` y positioning.l arms 2 4. Whenilthe ewindinezietfthe.-fllter 1 element has been compl ted, the... leaderrstrip I2,5;isgseoured tothe body:.otithefunittoprevent: unwindingrlof the oorrugated paper;

Irl-Ficken alternative-method offmanufactute l I -n this; particular.- embodiment bothfthe corrugated strip aresealed by; use of edge-Off theepapen- Strin..25: The.- cementis de The alternate iiute openings Il] are sealedV f1.3.; ansifbyaitspressure forces. upwardly-facing;.flutessd asftofproperlr close; tA emi.. '111142: Spring; loading onfrtthe .1 pressure;` roll 218iis; supplied; by v means off the springs 2| and 22 which operatebetween the.

.Iliugatedf paper; filter.;- element, is illusk -fuidzicement A cerrugatedpaper strip posited from the extruder nozzle 34 in suicient amount to fill the upwardly extending flutes at the edge of the strip. As the cemented corrugated strip is wound about the core, the cement serves to seal alternate flutes at opposite ends. The spring loaded pressure roll 35 is employed here as in the device shown in Fig. 3 to assist in forming a tight even wind of the corrugated paper; When theI winding. of;` the, corrugated paper-strip hasv been completed; the leader strip 36 is secured to the body of the unit to prevent uri-winding.

The Single faced corrugated paper employed as the ltration medium in this invention may be Ymarmiacturedaccording to the accepted practice hereihheforedescribed. The quality of the paper material chosenlfrorethe manufacture of the single faced corrugated paper may be varied widely depending `upon the purpose for which the filter isrto be used. We have-found that the unsized kraftpapers; ci about 9` `tdlZf thousandths orf-:gan inch in caliper, such as. are normallyused in the I preparation- A of,a standard, corrugated papelz are? quite satisfactory for ordinary ltration purposes.

l Special papers; specically prepared. for ltration` purposes may likewise be usedfeifectively. Itis., contemplatedthatthose familiar Ywith* the-artavl readilyvadaptpthef inventionrtofthe use-of. any.V speciiic type ofpaper tofsolve especial problem` confronting; them. The-paper materialsv used in` the fabrication yot thev corrugatedv stripz for the present filter.- unit f, should.. be of` sufficiently l low degree of hydration as to be readily permeable by thefluidsfto bei. ltered,while,at the-Same tiillc, being; of. sufficient densityy to prei/'entitheA passage of. solid particlesI therethrough. if a: highdegree oi .rigidity isl desired. in; thevlter unit, papers of.. the above-described,v nature may be. mpieshatedwith synthetic resins such as those. of the phenolic type.

Ii,. a;very high degree-otstreuglthfand rigidity is:desiredfinthe.ltenunitiitmay befimpreeuated witha; suitable sizingA solution... AY-`5,% solution@ ofta-v phenolic resininethyl alcoholis an; example of.,a.sizing.impregnant satisfacterufor thisapllrpose.` Onefprocedurefisto. dip. the filter unitin the resin solution.al1ow itto drain., andtheudry. it in an .oven at sufficient ,temperatiuefto curethe resln.A

In. thea manufacture; of; single.- aeed corrur gatedpaper'for, the .purposeot this .invention it is .desirable to faluricate the paper in relatively` wide widths and then to slit the Wide striuinto` narrower strips; of the required: width forY indivldualzlter; elementa,

A number or alternative methods willfbe Y'suggested, to.. those, familiar. with. the., corrugated paper art andtheexamples describedhereinare; intendedto be merelyV illustrative, of.. the. broad idea.. For` example, in Eig. the. application, of cement toopposite sides of. the, corrugated. web requires that a nonebonded..alea .b'epresentbef tween theV corrugated. sheet.. and. tha at, sheet along one` edge. tofacilitate the. introduction. of cement. between the two. sheets. Non-bonded areas of this nature are readily obtained by platzing` wipers on. thefadhesive applicator, rollfoflthe corrugating machine. and spacingY them improper.. relation to. the ,slitterfknivessothat.slitting takes. place. neanthezmiddle vof l the .nonfbonded area;

In another method of constructiom thefopenx endsd of the corrugationsare closed by., flattening the, corrugationspalongyone edge; and, sewing them shut;. Thismethodof closure may be facilitated the proper area during the slitting operation. Here again it is considered that the details of such procedures will be apparent to those familiar with the art of manufacturing corrugated paper.

Continuing with the description of the drawings, Fig. shows a side view in partial section of the assembled filter element employing the corrugated filter medium disclosed in Figs. 1 to 4. In this particular embodiment the lter element is adapted for use in an automotive engine for filtering the lubricating oil. The cylindrical corrugated filter medium 31 is fitted with formed sheet metal ends 38 and 39 to adapt it for mounting in a conventional automotive type filter casing. The core 40 may be seen extending at either end of the corrugated filter medium 31 to thereby support the metal adapter fittings 38 and 39. The metallic adapter 39 is bonded in fiuid tight engagement with the corrugated element 31 by means of a sealing compound 4|. The bottom end of the core 49 is provided with one or more holes 42 through which the filtered oil is allowed to pass to the exit standpipe of the oil filter housing. The metallic adapter 38 has an opening 43 therein to allow the filter element to be mounted on;

the standpipe of a conventional filter casing. A similar opening 44 in the metallic adapter 39 serves a similar purpose.

Fig. 6 is a top plan view of the filter element shown in Fig. 5. In this View the central annular opening 43 in the top metallic adapter is clearly shown. The fiuid tight bond between the corrugated medium 31 and the lower metallic adapter 39 is also shown. In Fig. 6 the sealing ends of alternate flutes are graphically represented.

'Ihe flutes which have open ends in Fig. 6 are sealed at the opposite ends. Hence, it will be evident that fiuid forced into the open utes at the top of the filter element in Fig. 5 must pass through the paper strips in order to emit from the open end of alternate flutes at the bottom of the filter element.

In Fig. 7 the partially sectioned side view of an automotive oil filter casing is illustrated. The cylindrical body 45 of the casing is fitted with a centrally located standpipe 46 upon which is mounted a replaceable filter element. A removable cover 41 forms the top of the housing. Fluid tight sealing with the body 45 is provided with the assistance of a gasket 48. The cover 41 is securely fastened by means of the bolt 49 threaded into the standpipe 46. Leakage about the bolt 49 is prevented by means of the fiber washer 58. The lower end of the standpipe 46 is fitted with a standard coupling 5I by means of which the standpipe is connected to the fluid outlet line 52. A similar coupling 53 is mounted on the side wall of the casing 45 and permits the introduction of fluid from the inlet line 54.

Mounted about the standpipe 46 and within the filter casing 45 is a filter element corresponding to that shown in Figs. 5 and 6. The corrugated filter medium 55 is shown in partial section so that the oppositely sealed ends of alternate corrugations are clearly shown. The filter element is maintained in position by means of the cork sealing washers 56 and 51 which are adapted to prevent leakage of fluid about the standpipe 46. The washers are held in fluid tight engagement with the metallic adapters 58 and 59 and about the standpipe 46 by means of the compressed spring 60. The spring in procedure, such Figs. 7 and 8, oil from the engine oil pump enters the casing through the inlet pipe 54 and the coupling 53 and is distributed throughout the open areas within the filter casing 45. When the cas-'f ing has filled with oil and oil enters the nonsealed flute openings at the upper end of the filter element as indicated by the iiow arrows. As the flutes fill with oil the oil is prevented from passing into the bottom of the lter element because these flutes are sealed at the lower end. The oil is then forced to pass through a layer of paper in order to reach a flute which is open to the exhaust side of the filter unit. At this point the solid particles contained in the oil are constrained from passing through the paper. The clean oil emits from the non-sealed flute openings at the lower end of the element as shown by the flow arrows. The cleaned oil is collected within the metallic adapter 58 and is forced to pass through the hole 42 into the hollow space between the core 4l) and the standpipe 46. The standpipe 46 has one o1' a plurality of holes 6| through which the cleaned oil flows into the standpipe and back through the outlet line 52.

It will be apparent that other equivalent means of performing the operations outlined herein may be used without departing from the spirit of the invention. It is intended that variations as'the added step of applying an adhesive to the tips of the corrugations during the winding operation, `so as to more firmly bind the unit together, be considered as part of this invention.

The cement used to seal or plug ings may be compounded of any materials that are resistant to the fluids to be filtered. The cement should be of a semi-fluid consistency so that it may be extruded readily onto the corrugations, but not so fluid as to flow out of position. The cement should be suiciently soft that it will be forced into the valleys of the flutes and form a secure bond in sealing the end of the utes when the corrugated strip is convolute wound about the core. The cement should not undergo excessive shrinkage during the drying operation since such shrinkage would prevent effective sealing of the flute openings. Phenolic resin varnishes bodied with llers such as wood flour, starch, kaolin, etc., make satisfactory cement compositions suitable for the present purpose. Other satisfactory cements will be obvious to those familiar with the art of compounding adhesives and sealing compositions.

It will be understood that the filtering unit disclosed hereinl is not limited to filtering the oil in automotive engines. The unit is also well adapted for filtering other types of fluids or for removing entrained particles in gases. While different applications of this nature would require minor changes in design and possibly different materials of construction, these changes are considered to be of a nature that anyone familiar with the art can apply. For example, the corrugated filter element may be fabricated from sheets of glass fiber mat or cloth rather than from paper, and the core of the filter element may be made of metal, plastic or glass. By employing these different materials of construction, it is possible to adapt the broad conthe flute opento the engine cept Qffrthis` invention toen; innumerable num-y bei'r of practical" applications.

The invention is, hereby. claimed asV follows:

1. A disposableflter element consisting essentially Q-acOrrugated web and a flat web convolutely wound, together, the adjacent flutes formed byv the corrugations alternately having one, end open and the` other end sealed, the sealing,` of one of'v said ends being eiected by pressing together the edges ofy said end and the sealingofjtheotherv ofV said ends being eliected by applyingl an. adhesive toopposite alternate openings,- said webs'being permeable to liquids and substantially non-pern'leableto solids and acting as they filtering medium. Y

2'A' disposableffilter element consisting essentially ot a, corrugated web having corrugations running-transversely and a flat web conn volutely wound intov a generally cylindrical body, saidV web sbeingformed of sheet material which isf permeable to liquidsy but substantially nonpermeable toA solids, the corrugations forming openings atvtheopposite edges of said body, and means sealingA said openings. alternately, the alternate openings on at least one edge being sealedwith a hardened cement.

3; A disposable lter element consisting essentially, of av corrugated web having corrugam tions,runningtransyersely andI a flat. web convolutely wound into a generally cylindrical body, :r

said, webs ,being formed of sheet material which is permeable to. liquids. but substantially nonpermeable to solids, the corrugations forming @menings` at the opposite edges of said body, and meanssealingsaid openingsY alternately', the-. alter t openingsA on the opposite edges being seals w hahardenedcement.

4., A'method of preparing; a disposable` filter.

element which comprises forming a continuous strip ot single-y faced corrugated.r sheet material cons,istingl ofY a corrugated web and a flat web which,a-refpermeable to liquids but substantially and plugging the ends of 5. A method. of, preparing; a disposable, filter: element. which comprises; applying; a Serif-hard-A ening-semi-fluid sealing*V adhesive adjacent the,

edge and between a continuousv strip of. corru-V gatedA sheet'material and a continuous. strip of flat sheet material, said sheet materials being permeable to liquids but substantiallyr non -p er. meable to solids, bringing said continuousstrips together with said adhesive securingv said strips;

y the flutes formedv between said corrugated` web and said at end to seal said ends of said utes adjacent one,- edge o the resultant continuous; strip o f materiaL filling thevv flutes on the surface of the c orr n.v gated` web which is Qmlositel theV surface adjacentI the dat web and o'nthe edge oppositeltharst mentioned edge withl al self-.hardening .semifluid adhesive whichjwhen set is notpermeable to liquids and serves to plug the flute-openings, and winding said continuous strips together to form` a body consisting ofA a plurality of layersofflutes. formed by vsaid webs, the cement in the corrugations when hardenedrfvorminga bond between layers of the wound material.

6. A method as` claimed in claim Llwherein thel flutes formed between the corrugated sheet maf.VV

terial and the flat web are sealed bysewing them; adjacent oneedge and the-utes onY the surface o the corrugated web which isopposite thel surface adjacent the nat web aresealed adjacent "ic edge opposite theY first mentioned edge with` a self-hardening semi-fluid cement which when set serves to plugv the liutevopenings and tovform; a bond between the layers of the wound material. i JORDAN V. BAUER.

Rossana n. confus.

affirmations crrnn The following references are, of record inthe; filo of this patent:

UNITED STAT-es Parleurs Number Name Datev 425,431 Hyatt Apr. 15, 1890 1,872,430 Ericson Aug. 16, 1932 2,196,821 Arnold Apr. 9, 1940 2,210,397 Driess Aug. 6, 1940 2,427,733 McCann Sept; 23, 1947I 5025425 Wellborn Apr. 4., 1950 FOREIGN PATENTS Number Country Date 535,153 Great Britain Mar. 1, 19M 330,/86 France Mar. 26, 1943 

